FireFox is set (soon I hope) to launch an innovation called Tab Candy. This will permit Firefox to act more like a OS. Kinda Chrome like if Google has their way. The focus of Tab Candy is multitasking and sharing. Tab Candy is managed by Aza Raskin, the Head of UX at Mozilla Labs. Raskin is the son of Macintosh creator Jef Raskin.
Tab Candy features:
Organize tabs into groups that you can name and position on a desktop-like view
Search and Save tab groups to look at later
Have multiple profiles so that you can sign into the same site with different logins in two different tab groups
Share tabs or tab groups between users, computers and devices (Smartphone supported)